This is a Phase II, multicenter, active controlled, 1:1:1 randomized 4 week parallel group study with three treatment groups (HOE901[30] HOE901 [80] and NPH-human insulin). The study consists of a 1-week screening phase, a 4-week partially double-blind treatment phase and a follow-up visit in NIDDM patients not optimally controlled on the maximum dose of a sulfonylurea.